Automatic telephone system



Jan. 25, 1921. 1,615,280

E. JACOBSEN AUTOMATIC TELEPHONE SYSTEM Original Filed March 13, 1919 v 2 Sheets-Sheet 1 5 HAT fi M EL lnuenfc7r- E'm1Z Jscmbsen.

Jan. 25 1927. 1,615,280

E. JACOBSEN AUTOMATIC TELEQHONE SYSTEM Original File d March 13, 1919 2 Sheets-Sheet 2 [nus rzfuz- Em'zZjac/zbserz m my.

Patented Jan. 25, 1927,

5 UNITED STATES 'P-ATEN a T *Q'FFIC'E-fi'fi EMIL'J'ACOBSIEN, on NEW roux; N, Y., AssIonoarYMEsNE AssIeNME N'rs, r0 Aura MATIC ELECTRIC me, or onroaeo, rumors. A coaromrron or DELAWARE.

AUTOMATIC TELEPHONE SYSTEM.

Application filed March 13,1915 serial in. 282,443,

My invention relates in general to automatic telephone systems and more specifically to an improved method of controlling certain of the switches in such a systenm A switch has been used in the past which has so called group selecting as well as trunk selecting functions, that is, one group of trunks from a switch may consist of 20 or 30 trunks and may take up two' or three levels in the switch. The switch may thus select automatically a trunk in any of the levels assigned to the group by a vertical and rotary trunk selecting movement. In the past such a switch has always operated to rotate past-busy levels in case all trunks are busy and rotate past all the trunks in the last level of the group to give a busy signal by closing a pair of cam springs on theeleventh rotary step.

This is objectionable in 'certam cases, as when an operator is using a switch ofthis character to call into a largefactory which has more than ten trunks of the same di-v rectory number she must of course release the entire connection and-call again in case all the trunks are busy.

The object of my invention is therefore to do away with the necessity of releasing the connection when all the trunks are busy and to so arrange the operation of the switch that when all the trunks in a multi level group are busy, the switch Will stop at its first vertical step leading to that group and will then give a busy signal'to the operator. The operator may in this manner set up the call and leave it until a trunk goes idle, at which time the switch will automatically step up and rotate or rotate only, depending upon the location of the idle trunk, and pick out that idle trunk. In case of a regular call from a subscriber, however, the switch operates in its regular manner and must be released it all the trunksare busy. p

These and other features of my invention will be explained more in detail by referring to the accompanying drawings in which,

V Fig 1 shows a substation A, having access through a line switch 0 to a special combination switch embodying my invention. This switch is also accessible to a toll selector of anyapproved type such as shown in Fig. 3 when the call is from-an operator in the main exchange.

Fig. 2 vshows one arrangement of the pri vate bank and its cooperating wipers of the switch H showing three levels of trunks in l one group.

In Fig. 3 I have shown a toll selector switch such as may be. used by operator in follows: Subscriber A upon removing his receiver to-initiate a call, closes a circuit in the usual manner for the line relay 2 of the line switch Gin series with the line circuit Relay 2 u on operating closes a circuit for relay 3 an ashort circuit around relay 3 to the private magnet 4 in series and also closes wipen; Now if the private contact of a trunk is grounded as a" result of its beingin' use, the magnet 4 will operate over this short circuitand step, the wipers on until an idle trunk is reached.- At this time relay 3 being no longer short eircuited will energize and cut the line throu h to the line re.- lay 5 of the switch lvfignet a does not energize in series with the relay 3.

. As soon as the switch H is seized the line relay 5 energizes and closes'a circuit for the slow relay 6 which in turn energizes to prepare thecircuit of the vertical magnet 7, to ground the holding trunk back to the line switch G, andt'o place ground on the multiple in the bank of the toll selectors through relay 62. ;Now when the calling.

device isoperated for thefirst digit,the line relay 5 responds thereto and closesa circuit" v for the vertical magnet. 7' extending from ground through springs 8 and 9, spr1hgs 1O and ma et? to hatter Each time the magnet operates the wipers of the switch are raised one ste to alevel of bank contacts: It may be nector H has a plurality-ofwipers, namely,

and 11, slow relay 12, springs 13, spring I v ,100 ere noted that this con-7 a vertical wiper 15- w-hich is located at the right of the'bank and which passes over aspecial-set of contacts 16 one for each level, as the switch steps vertically; a chain wiper 18 which operates to carry the ground from the first contact 21 in the bank to the last contact 22 when all the trunks are'seized; a private wiper 17 of the usual character,

and a pair of line wipers 19 and 20. The bank of this switch may of course be split up into any desired number of groups and the particular arrangement shown is only an alternative way of dividing the trunks. In Fig. 2 I have shown the first 3 levels as forming a group by itself and the next 2 levels may form another 'roup by themselves. Now if the firstdlgit is one the magnet 7 will step all the wipers to the first level of contacts with the Wiper 15 in engagement with the first or lower contact 16. Now if all the trunks in the first level have been seized by other switches then the various chain wipers such as 18 of the oc cupying switches will have carried the ground from the first contact of this level to the relay 23 which will therefore operate to place ground through the resistance 39 on the group contact 16, and it all the trunks in the three levels are busy then all three relays 23, 40 and 41 will be energized and will jointly connect ground to the lower contact 16. As soon as the switch steps off normal the circuit of relay 24 is closed from ground through springs 25, springs 26 and 27, springs 28 and 29, relay 12 being ener gized in series with the vertical magnet, and through otl normal springs 30 and relay 24: to battery. Relay 24 energizes and closes a new circuit for itself from springs 25 through springs 31, springs 32 of the vertical magnet 7, springs 33 of rotary magnet 34, and through oil normal springs 30 to relay 24 and battery. Relay 24 also closes the springs 35 which prepare a circuit for the rotary magnet 34:. r

If, however, as pointed 0ut,'a ground is present on the contact 16 associated with the level selected, then a circuit will be closed for the relays 36 and 37 in series with the test wiper 15. Both of said relays will energize at this time and relay 36 opens the springs 14 which is of no effect at this time due to springs 38 being closed. Relay 37 upon'energizing, opens a circuit for the rotary magnet at springs 42 and 43 and closes a new circuit for the vertical magnet 7 at springs 43 and 44. Now when relay 12 falls back after this first digit a circuit will be closed extending from ground through springs 25, springs 26 and 27, springs 23 and 45, springs 35 of relay 24, springs 43 and 44, springs 38, and magnet 7 to battery. Magnet 7 now operates to step all the wipers to the second level of the group and opens the circuit of relay 24. at springs 32. The said springs 32 remove a short circuit from a high resistance lower winding of relay 37 to maintain said relay energized as Wiper 15 passes to the next contact but relay 24 falls back and again opens the circuit of magnet 7 at sprin s 35. Now as all the trunks in the three levels are busy, relay 37 remains energized after magnet 7 de-energizes and again closes contact 32, relay 2 1 is again energized, this time over a new circuit through the upper springs of relay 37, and the alternate action continues until the wiper 15 meets a nongrounded contact 16 which in this case will be the third vertical contact. At this time relays 36 and 37 will no longer be energized, although relay 37 is rendered slightly slowncting by the closure of springs 32 .on the last de-energization of magnet 7 and holds up long enough to enable relay 24: to energize once more. fhis does not re-operate magnet 7, however, be cause relay 37, on deenergizing, opens the circuit of the vertical magnet and closes the circuit of rotary magnet 3% from ground through springs 25, springs 26 and 27, springs 28 and 45, springs 35, springs 4:3 and 42, and rotary magnet 34: to battery. Magnet 34; will now energize to break the circuit of relay 2 1-- and to step the wipers into engagement with the first set of con tacts in the upper level of the group. 'llhat is, the wiper 15 will move to the right, away :l'roin contact 16, the wiper 17 will engage the lower contact of the first pair of contacts and the right hand one of the double wipers 18 will rest on contact 21. Now if all the trunks in this last group are busy a ground will be met by the wiper 17 which will again energize relay 24: which now opcrates alternately with the rotary magnet 34, each interrupting the circuit of the other until the wipers are rotated past the last set of contacts on the bank and a set of rotary off normal springs 46 are closed to connect a busy signal to the line.

Now, however, assume that all the trunks in the first level are busy and there are one or more idle trunks in the second level. Then relay 23 will be energized to connect ground through a resistance on the first contact 16, but relay 40 will not be energized and therefore there will be no ground presout on thesecond contact 16. The switch ll will therefore be operated in the usual manner as pointed out in connection with the previous call and when wiper 15 meets the first contact 16 which is grounded through resistance 39 the relay 37 will energize but relay 36 will not. The vertical magnet 7 will again be operated to step the wipers to the second level of the group as before. Now when the wiper 15 meets the second contact 16 which is not grounded, the relay 37 will fall back and start the rotary as before and the wipers will start in search of an idle trunk in this level, testing each with the wiper 17. As soon as wiper 17 meets an idle trunk and a contact having no ground the relay will remain deenergized and therefore the rotary magnet 34 will not again energize and the wipers will come to rest on the set of contacts associated with the idle line. As soon as the crating wipers come to rest on an idle line a circuit is closed from ground through springs 25, through the winding of relay 17, through springs48 and 49, wiper 17, and through the usual cut off relay of the called line to battery. Relay 47 energizes to cut the talking circuit through to the Wipers 19 and 20 and is held energized by a circuit from springs 25 and ground, through relay 47, springs 32, springs 33-, springs 30 and winding of relay 24 to battery. vRelay 17 connects ground direct to wiper 17 to make the called line busy, and opens the circuit of the magnet 7 at springs 13. Assoon as the springs 50 and 51 make contact the ringing circuit for the called line is closed from the ringing machine R through springs 52 and 53, springs 5 1 and 55, springs 51, wiper 20, to and through the ringer of the called station, and back over wiper 19, springs 50, springs 56 and 57, springs 58 and 59, and upper winding of ring out off relay 60 to battery. As soon as the called subscriber answers a direct current circuit is closed for the relay 60 which energizes to cut off the ringing and connect the back bridge relay 61 to the called line. Relay 61 energizes in series with the called line, supplying battery to said called line for talking purposes and reversing the battery connections to the calling line in the usual manner. Conversation may now proceed and the connection will be released by the hanging up of the receivers at the calling and called stations.

I will now describe the operation of the apparatus when a call comes in to the switch H from the selector E (Fig. 3). This selector shown in Fig. 3 usedfor calls from an operator to an automatic exchange and its operation will be only generally described, as switches of this type have been used before.

When this selector E Fig. 3 is seized it is operated through the medium of the line relay 76 which controls the vertical and rotary magnets 77 and 78 to step the wipers into engagement with the contactssuch as 63,6 1, and 66 leading to the connector H (Fig. 1). As soon as the switch H is seized, the relay 79 of switch E energizes to connect the bridged relay 98 across the talking circuit and to close a circuit through resistance 75, springs 74 and 73, springs 72 and 71, wiper 70, contact 6 1, relay 62, to the spring of relay 6 of switch H. Also an opcircuit isclosed from ground through springs 81 and 82 of the line relay 76 of switch E, springs 83 and 84, wiper 85. contact 63-3, upper winding of relay 67, and upper winding of the line relay 5 of the switch H to battery. Relay 5 of course energizes and operates relay 6, to connect ground tothe above traced circuit through the relay 62 and the resistance of the selector E. Now when relays 62 and 67 enis a type of switchcrgize, the springs 88 are opened around the resistance 86, springs 58 and. 87 are closed, the springs 88 are closed to hold rclay67 energized and the springs 52 and 53 are opened in the ringing circuit. -Now as the operator operates the dial, relay 76 of the selector E operates and in turn controls relay 5 of switch H to in turnoperate the magnet 7 as in a local call to step the wipers 15, 17, 18, 19' and 20 to a level of. the banks or to the first level of a roup of levels such as shown in Fig. 2 in which it is desired to. select an idle trunk or called line.

Assuming now that tl'iere is an idle trunk in the upper level of this three level group then the lower two contacts will be connected to ground through a resistance 39. When wiper 15 meets the first of these two contacts 16 and pauses there, then relay 37 will be energized but relay 36 will not. springs 13 and 44 will be closed and springs 1 1 will remain closed, so that relay 2- at springs 35 will completea circuit for the magnet 7 to step the wipers to the second contact and to open the circuit of relay 2 1 at springs 32. When wiper 15 meets the next or second contact 16 the same operation occurs and magnet 7 is again energized to step the wipers to the third level of the group. The contact 16 ot' the third level being open, no circuit is closed for relay 37, this relay deenergizes, and the circuit of magnet 34 is closed through springs 35, 43 and 42 to step the wipers in onto the lirst set ot' contacts in this level at which time the wiper 17 becomes effective to continue the rotation of the wipers into connection with an idle set of contacts. After the called line is found the operator presses her ringing key and energizes relay 99 oi the selector E to close a circuit for the relay 91. through springs 92. Relay 91 operates to open the circuit through resistance 75 and relay 62 of the switch H. Relay 62 decnergizes to connect the ringing circuit through contacts 52 and 53, 541 and to and through the ringer oi the called line, back through Wiper 19, springs 50, springs 56 and 57, springs 58 and 87, contact 65, springs 93, springs 94 and 95, and slow relay 96 to but tery. swcrs, relay 96 energizes to open the locking circuit of relay 91 atsprings 97. Finlay. 91 falls back and connects the back bridge relay 98 across the called line and to again close the circuit of relay 62, which energizes to disconnect theringiugcircuit and close the spring 53 and its front contact which causes relay 98 to energize in series with the called line and gire a signal to the operator.

Assume now that all of the sets of contacts in all three levels of the desired group are busy, then all three relays 23. 46, and 41 will be ci'iergized and will connect a direct ground to the lower contact 16. Now when There to re 1 As soon as the called subscriber allthe operator is operating this switch H and the wiper 15 meets this grounded contact 16 which is connected to direct ground, then relays 36 and 37 will both be energized in serieswith wiper 15. Now when the operation of the switch II (JOHNS to this point the circuit of the vertical magnet is ditl'erent from what it formerly was and now passes from ground through springs 25, springs 26 and J7, springs 28 and 45, springs 35, springs 43 and 44. resistance 86, and magnet 7 to battery. Both springs 38 and 14: being open and resistance 86 being high enough to prevent the operation of magnet 7, then the switch will stop at this point. Relay 36, upon energizing closes the springs 100 to connect a busy tone to a conductor of the talking circuit. The operator upon hearing this signal knows that all the lines are busy to this group of telephones but instead of releasing the connection she will simply leave it set up and wait until one of the lines becomes idle. When any line in this group becomes idle the circuit of the relay corresponding to its level is opened and therefore the chain conncctii'ig ground to the first contact 16 is broken. It the idle trunk is in the second level, then relay 4() will dcencrgizc, thus breaking the direct ground connection and leaving ground through resistance 35) connected to the first contact 16. When this occurs the relay 3t will deencrgize but relay 3? will remain energized. h' 'n'ings 14; of relay 36 now close contact to short out the resistance 86 in series with the vertical magnet and magnet 7 will therefore operate to step the wipers to the second level and to the second contact 16, which is open at this time. Relay 37 will now deenergize also and open the circuit of magnet 7 and close the circuit of magnet 34 which as before will cause the wipers to rotate in Search of the idle trunk. p

It will be seen there fore that I have provided an automatic switch which has vertical and rotary automatic selecting operations, one which, when used by a calling subscriber in the same exchange, will operate to the last set of contacts in the last level assigned to the wanted'group, and give .1 busy signal when all the trunks in the group are busy, and one which, when used by an operator in another exchange, will stop on the first movement bringing the wipers opposite the first level assigned to the group when all the trunks therein are busy, and which is so arranged that when any trunk in the group becomes idle, the switch will automatically operate to pick out the particular idle contact and its level and cut through. Thus a calling subscriber must alwayshang up his receiver and call again when he receives a busy signal but an operator may leave a connection set up when a busy signal is received and the connection will be automatically completed when a line becomes idle.

Having fully described and ascertained the features and aspects of my invention. what I consider to be new and desire to have protected by Letters Patent will be pointed out in the appended claims.

What I claim as my invention is:

1. In a telephone system, a trunk seleetinz: switch havinga wiper and trunk lines accessible thereto divided into groups, said wiper having a primary motion to pick out a group and a secondary motion to select an idle trunk in a group, means for stopping the movement of the wiper after it has completed the primary movement and before the secondary movement has started when all of the trunks in the selected group are busy, and means for causing said wiper to operate both in its primary and secondarymovements to move into engagement with a trunk as soon as one becomes idle.

2. In a telephone system, a trunk selecting switch having wipers and trunk lines accessible thereto divided into groups and subgroups, means for moving said wipers opposite a group of trunks but out of engagement therewith, means for making all of the trunks busy, means for preventing further operation of the wipers when all the trunks are busy untila trunk in one of the subgroups becomes idle, and means for the bringing said wipers first opposite the subgroup in which there is an idle trunk and then into engagcn'ient with said idle. trunk.

23. In a telephone system, a trunk selecting switch having a wiper and trunk lines accessible thereto divided into groups and subgroups, a test contact for each trunk line, a test contact for each subgroup of trunks, the test contact of one subgroup also serving as a test contact for the group, means for making the trunks busy, means for moving said wiper into engagement with the test contact of a group and means for preventing further operation oi the switch it all the trunks are busy.

4. In a telephone system, a trunk selecting switch having a, wiper and trunk lines accessible thereto divided into groups and subgroups, a test contact for each trunk line a test contact for each subgroup of trunks, the test contact of out-subgroup also serving as a test contact for the group, means for making the trunks busy, means for moving said wiper into engagement with the test contact of a group and means for moving said wiper into engagement with the test contact of another subgroup it only the trunks in the first subgroup are busy.

5. In a telephone system a trunk selecting switch having line and test wipers and trunk lines accessible to said wipers each having a test contact. said trunk lines divided into groups and subgroups with a test contact'for each subgroup one of which acts as test contact for the group, means for moving the wipers until the test wiper engages the test contact of a group, means for stopping the switch at this time it all the trunks in all the subgroups of this group are busy and means for moving the wipers to the test contact of another subgroup in the group of trunk lines and then rotate and connect to an idle trunk in the selected idle group, and means made operative if all trunks are busy to prevent the said automatic vertical motion.

7. In a telephone system, a switch having a wiper, a group of trunks divided into subgroups accessible to said wiper, said wiper having primary and secondary movements, direetively. controlled means for operating said wiper in its primary movement to pick out a subgroup. of trunks, means operable thereafter in case said subgroup of trunks is busy for operating said wiper automatically in its primary movement to pick another of said subgroups, meansoperable after an idle subgroup is found for operating said Wiper in its secondary movement to bring it into engagement with an idle trunk, and means operable when all of said trunks are busy for preventing the said automatic primary movement of said wiper.

8. In a telephone system, a switch having a wiper, a group of trunks divided into subgroups accessible to said wiper,'said wiper having primary and secondary movements, direet-ively controlled means for operating said wiper in its primary movement to pick out a subgroup of trunks, means operable thereafter in case said subgroup of trunks is busy for operating said wiper automatically in its primary movement topick another of said subgroups, means operable after an idle subgroup is found for operating said wiper in its secondary movement to bring it into engagement with an idle trunk, and means operable when all of said trunks are busy for preventing the said automatic primary movement of said wiper until after one of said trunks has become idle.

9. In a telephone system, a switch having awiper, a group of trunks divided into subgroups accessible to said wiper, said wiper having rimary and secondary movements, means or operating said wiper in its primary movement to pick out a subgroup of trunks, means operable thereafter in case said subgroup of trunks is busy for operatmg said wiper automatically in its primary movement to pick anotherof said subgroups, means operable after an idle subgroup is found for operating said wiper in its secondary movement to bring it into engagement with an idle trunk, and means operable when all of said trunks are busy for preventing the said automatic primary movement ofsaid wiper until'after one of said trunks has become idle.

10. In a'telephone systeima switch having a wiper, a group of trunks divided into subgroups accessible to said wiper, said wiper having primary and secondary movements, directively controlled means for operating said wiper in its priniar 1 movement to pick out a subgroup of trun s, means operable thereafter in case said subgroup oftrunks is busy for operating said wiper automatically in its primary movement to pick another of said subgroups, means operable after. an idle subgroup is found for operating said wiper in its secondary movement to bring it into engagement with an idle-trunk, and means operable in case all of said trunks are busy for maintaining said switch in condition tobring said Wiper into engagement with any one of said trunks. after it becomes idle.

11. In a telephone system, a switch havin a wiper, a group-of trunks divided into su groups accessible .to said wiper, said wiper having rimary and secondary movements, means or operatin said wiper in its primary movement to icl i out-a subgroup of trunks, means opera is thereafter in case said subgroup of trunks is busy for operating said wiper automatically in its primary movement to pick another of said subgroups, means operable after an idle subgroup is found for operating said wiper in its secondary movement to bring it into engagement with an idle trunk, and means operable in case all of said trunks are busy for main taining said'switeh in condition to bring said wiper into engagement with any one of said trunks after it becomes idle.

12. In a telephone system, a switch having a wiper, a group of trunks divided into subgroups accessible to said wiper, said wiper having primary and secondary movements, means for operating said wiper in its primary movement to pick out a subgroup of trunks, means operable thereafter in case said subgroup of trunks is busy for operat ing said Wiper automatically in its rimary movement to pick another of said su groups means operable after an idle subgroup is found for operating said wiper in its secondary movement to bring it into engagement with an idle trunk, and meansoperable in case all of said trunks are busy for testing them continuously.

i i. .In a tele 'ihonc system, a, switch having a wiper. a group of trunks divided into sub groups accessible to said wiper, said wiper having primary and secondary movements,

means for operating said wiper in its primary movement to pick out a subgroup of trunks, means operable thereafter in case said subgroup of trunks is busy for operating said wiper automatically in its prinia v W movement to pick another ofsaid subgrou s,

means operable after an idle subgroup is found for operating said wiper in its secondary movement to bring it into engage ment with an idle trunk, and means operl5) able in case all of said trunks are busy for sible by way of two paths, said switch having a wiper, a group of trunks divided into subgroups accessible to said wiper, said wiper having primary and secondary movements, means for operating said wiper in its primary movement to pick out a subgroup of trunks, means operable thereafter in case said subgroup of trunks is busy for operating said wiper'automatically in its primary movement to pick out another of said subgroups, means operable when the primary movement is completed for operating said wiper in its secondary movement to bring it into engagement with an idle trunk, means operable in case all of said trunks are busy for preventing any further movement of said wiper after the first said primary movement is completed in case said switch has been seized by way of a'particular one g ot" said paths, and means "for rendering said 40 last means inoperative in case the switch has been seized by way of the other of said paths.

15. In a telephone system, a switch, a group of trunks accessible thereto divided into subgroups, a test contact for each trunk and a test contact for each subgroup, the test contact of one subgroup serving also as the test contact for the group, means for placing a certain busy potential on said 0 group test contact when the associated subgroup is busy, and means for placing a different busy otential on said group test contact when tiie group is busy.

16. In a telephone system, a switch, a

5 group of trunk lines accessible to said switch divided into sub-groups, a test contact in said switch, means for placing a certain busy potential on said test contact when one of said sub-groups is busy, and

means for placing a different bus potential on said test contact when all 0 said subgroups are busy. I

17. In an automatic trunk selecting switch having both directive and automatic primovement, means for automatically and successively starting the automatic movements of said switch upon completion of the direc tire movement. and means ctt'cctive contingcnt upon the busy condition of trunk lines accessible to said switch for preventing both automatic movements.

18. In an automatic trunk selecting switch having both directive and automatic primary movements and an automatic secondary movement, means for automatically starting the automatic primary movement of said switch responsive to the completion of the directive movement, means for automatically starting the secondary movementof said switch upon completion of the automatic primary movment, and means ettective contingent upon the busy condition of trunk lines accessible to said switch for rendering the said first starting'means ineffective.

19. In an automatic trunk selecting switch having both directive and automatic primary movements and an automatic secondary movement, a group of trunk terminals selectable by a predetermined directive primary movement, means for automatically and successively starting the automatic movements of said switch upon-completion of the directive movement, means effective in case all said terminals are busy when the group is selected for preventing any automatic movement of. said switch, and means for startin the automatic movements to select an idle trunk terminal as soon as one becomes available. I

20. The combination, with an automatic switch and means for operating the same, of a plurality of trunk lines accessible to said switch consequent upon its operation but only by two successive subsequent operations in different directions, means for causing the switch to automatically perform the two last mentioned operations responsive to the completion of the first operation, means effective in case all said trunk lines are busy for retaining said switch in its initial operated position, and means effective upon any trunk line becoming idle for operating the switch to select the same as set forth.

21. In a combination toll and local connector, means for operating the switch in a directive primary movement and in automatic primary and secondary movements to select a trunk line by group, sub-group, and individual selecting operations, respectively, and means efl'ective in case said switch is in use as a toll connector for holding the same in a state of suspended operation at the end of its directive primary movement provided the group of trunks selected in such primary movement is busy.

22. In a combination toll and local connector, means for operating the switch in a directive primary movement and in auto- 65 mary movements and an automatic secondary matic primary and secondary movements to lies? AVAEL select a. trunk line by group, subgrt'iup, and individual selectingoperations, respectively, means ellertivc in (use said switch is in use as a, toll connector for holding the some in a state of suspended operation at the end of its directive primary movel'ncut provided the group of trunks selected in. such primary movement is busy, and means for automati- (filly continuing the operation-of the switch to select a sub-group and a trunk in such suh-group as soon as a sub-group is available containing an idle trunk.

2;}. The combination, with an automatic switch accessible over two different paths, of groups of trunks divided into sub-groups,

EMIL JACOBSEN. 

